This core provides the overall management and administrative support for the Program Project grant, mainly related to the multicenter selective lymphadenectomy trials (MSLT) I and MSLT-II, which are at the heart of the entire grant. The John Wayne Cancer Institute (JWCI) database, which includes data on about 14,000 patients who are not enrolled in the MSLT studies, also operates under Core B and supports studies proposed in Projects I, II, and III. In addition, this core coordinates the collection and management of patient specimens (serum and tumor tissue). Finaly, Core B also provides the support for the overall administration of the Program Project, an important part for the integrity of the grant. To consolidate the core activities around the multicenter clinical trials, in this renewal, we conceived a large, complex core that combines the duties of the past Cores B and C ([unreadable]Research Support[unreadable] and [unreadable]Administrative Service and Multicenter Trial Operations Center[unreadable], respectively) and provides essential support to all projects. This consolidation was possible only due to the strong unity of this grant around the multicenter clinical trials MSLT-I and MSLT-II, around which gravitate all three projects and cores. the specific aims of Core B are: 1) to fulfill all the duties and responsibilities of a multicenter trials operations center for MSLT-I and MSLT-II, including the MSLT-I and -II databases administration;2) to support the JWCI databse administration;3) to sustain the collection, processing, archiving, and retrieval of serum and tumor tissue specimens from the MSLT and JWCI sites; and 4) to provide administration to the individual projects and cores of the Program Project. In conclusion, this large and complex administrative core concentrates the grant administration, multicenter clinical trial operations, JWCI database administration, and the collection of important specimens supporting aims in all projects of the grant.